<?php
namespace app\cls\tom;
class JsSDK {
  private $appId;
  private $appSecret;
  private $redis;

  public function __construct($appId, $appSecret) {
    $this->appId = $appId;
    $this->appSecret = $appSecret;
    $this->redis = SysResource::getRedis();
  }

    /**
     * 获取分享的签名
     * @param $url
     * @return array
     */
  public function getSignPackage($url) {
    $jsapiTicket = $this->getJsApiTicket();

    if(!isset($url)){
      // 注意 URL 一定要动态获取，不能 hardcode.
      $protocol = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off' || $_SERVER['SERVER_PORT'] == 443) ? "https://" : "http://";
      $url = "$protocol$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";
    }

    $timestamp = time();
    $nonceStr = $this->createNonceStr();

    // 这里参数的顺序要按照 key 值 ASCII 码升序排序
    $string = "jsapi_ticket=$jsapiTicket&noncestr=$nonceStr&timestamp=$timestamp&url=$url";

    $signature = sha1($string);

    $signPackage = array(
      "appId"     => $this->appId,
      "nonceStr"  => $nonceStr,
      "timestamp" => $timestamp,
      "url"       => $url,
      "signature" => $signature,
      "rawString" => $string
    );
    return $signPackage;
  }

  private function createNonceStr($length = 16) {
    $chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
    $str = "";
    for ($i = 0; $i < $length; $i++) {
      $str .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);
    }
    return $str;
  }

  private function getJsApiTicket() {
    // jsapi_ticket 应该全局存储与更新，以下代码以写入到文件中做示例
    $ticket_old = $this->getCache(REDIS_PREFIX."jsapi_ticket");
    if($ticket_old){
        $data = json_decode($ticket_old);
    }else{
        $data = null;
    }
    if (empty($data) || $data->expire_time < time()) {
      $accessToken = $this->getAccessToken();
      // 如果是企业号用以下 URL 获取 ticket
      $url = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?type=jsapi&access_token=$accessToken";
      $res = json_decode($this->httpGet($url));
      if(isset($res->errcode) && $res->errcode != 0 ){
          throw new \Exception("获取票据错误,code=>{$res->errcode},msg=>".$res->errmsg);
      }
      $ticket = $res->ticket;
      if ($ticket) {
        $data->expire_time = time() + 6900;
        $data->jsapi_ticket = $ticket;
        $this->setCache(REDIS_PREFIX."jsapi_ticket", json_encode($data));
      }
    } else {
      $ticket = $data->jsapi_ticket;
    }

    return $ticket;
  }

    /**
     * 获取公众号access_token
     * @return bool|string
     * @throws \Exception
     */
  public function getAccessToken() {
    // access_token 应该全局存储与更新，以下代码以写入到文件中做示例
      $key = REDIS_PREFIX."access_token";
      $access_token = $this->getCache($key);
      if($access_token){
          $data = json_decode($access_token);
      }else{
          $data = null;
      }
    if (empty($data) || $data->expire_time < time()) {
      // 如果是企业号用以下URL获取access_token
      // $url = "https://qyapi.weixin.qq.com/cgi-bin/gettoken?corpid=$this->appId&corpsecret=$this->appSecret";
      $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=$this->appId&secret=$this->appSecret";
      $res = json_decode($this->httpGet($url));
      if(isset($res->errcode) && $res->errcode != 0 ){
          throw new \Exception("获取token错误,code=>{$res->errcode},msg=>".$res->errmsg);
      }
      $access_token = $res->access_token;
      if ($access_token) {
        $data->expire_time = time() + 5000;
        $data->access_token = $access_token;
        $this->setCache($key, json_encode($data));
      }
    } else {
      $access_token = $data->access_token;
    }
    return $access_token;
  }

    /**
     * 获取公众号access_token [刷新缓存]
     * @return bool|string
     * @throws \Exception
     */
    public function getAccessTokenRefresh() {
        // // access_token 应该全局存储与更新，以下代码以写入到文件中做示例
        $key = REDIS_PREFIX."access_token";
        // $access_token = $this->getCache($key);
        // if($access_token){
        //     $data = json_decode($access_token);
        // }else{
        //     $data = null;
        // }
        if (empty($data) || $data->expire_time < time()) {
            // 如果是企业号用以下URL获取access_token
            // $url = "https://qyapi.weixin.qq.com/cgi-bin/gettoken?corpid=$this->appId&corpsecret=$this->appSecret";
            $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=$this->appId&secret=$this->appSecret";
            $res = json_decode($this->httpGet($url));
            if(isset($res->errcode) && $res->errcode != 0 ){
                throw new \Exception("获取token错误,code=>{$res->errcode},msg=>".$res->errmsg);
            }
            $access_token = $res->access_token;
            if ($access_token) {
                $data->expire_time = time() + 5000;
                $data->access_token = $access_token;
                $this->setCache($key, json_encode($data));
            }
        } else {
            $access_token = $data->access_token;
        }
        return $access_token;
    }

    /**
     * 下载媒体资源
     * @param $mediaId
     * @param $downloadPath
     * @return bool|int
     * @throws \Exception
     */
  public function downloadMedia($mediaId,$downloadPath)
  {
      $path = dirname($downloadPath);
      if(!file_exists($path)){
          mkdir($path,0777,true);
      }
      $token = $this->getAccessToken();
//      $mediaId = urlencode($mediaId);
      $url = "http://file.api.weixin.qq.com/cgi-bin/media/get?access_token={$token}&media_id={$mediaId}";
//      echo $url;
      $content = @file_get_contents($url);
      $bytes = strlen($content);
      if($bytes < 150){
          throw new \Exception("微信素材下载报错,【{$content}】");
      }
      return file_put_contents($downloadPath,$content);
  }

  private function httpGet($url) {
    $curl = curl_init();
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($curl, CURLOPT_TIMEOUT, 500);
    // 为保证第三方服务器与微信服务器之间数据传输的安全性，所有微信接口采用https方式调用，必须使用下面2行代码打开ssl安全校验。
    // 如果在部署过程中代码在此处验证失败，请到 http://curl.haxx.se/ca/cacert.pem 下载新的证书判别文件。
    curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, true);
    curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, true);
    curl_setopt($curl, CURLOPT_URL, $url);

    $res = curl_exec($curl);
    curl_close($curl);

    return $res;
  }

  private function getCache($cachename){
    //TODO: get cache implementation
    $value = $this->redis->get($cachename);
    if($value){
      return $value;
    }
    return false;
  }

  private function setCache($cachename,$value,$expired=7000) {
    $ret = $this->redis->set($cachename,$value,$expired);
    return $ret;
  }
}

